Speed governor



5 Sheets-Sheet 1 l. J. SNADER SPEED GOVERNOR Dec. 21, 1948.

Filed DSC. 17, 1945 l. J. SNADER SPEED GOVERNOR Dec. 21, 1948.

5 Sheets-Sheet 2 Fil'ed Dec. 17, 1943 l. J. SNADER SPEED GOVERNOR Dec. 21, 1948'.

Filednec. 17, 1945 5 Sheets-Sheet 3 F057' RWE makina: Pim" SLOW RATE /mfnae Wmv DEV/cs DE Y/C E l. J. SNADER SPEED GOVERNOR Dec. 21, 194s.

Filled Dec'. 1'7, 1945 5 Sheets-Sheet 4 1. J. sNADER 2,456,746

SPEED GOVERNOR Dec. 21, 194s.

5 Sheets-Sheet 5 Filed Dec. 17, 1943 MNN Patented Dec. 21, 1948 znssnis Sl'EED GOVERNOR IraifJ Snadenri. Detr'nit, Minna(assignorstior Ayom Manufacturing; Corporation. at corporation: ofr- Delaware- A-ppiicmen December 17, 1943i,v seriarNo; ys147729- 3 (llaimsi:`

. 1' The present' invention rel'atesfgenerallwtogovernorse More particularly" the* invention'L relates to tliathtyper of governorI whichi is primarily de signed for" usev` in. connectionk Withanirairpl'ane having acontrollable' pitch propellenand arprorp'ellerf driving inter-nal combostiony engine; and 'operates by vary-ing thepitch of theI propeller blades: to .control or' govern the enginev southat" it operates. at a predetermined speed'.

O'neobject ofthe inventionf is to provide `azgovfi Ierrior ofi this type whichris an'improvementupon,

andi ls-l` more efficient than; previouslyfd'esigned governorsforA the same purpose.

@Another object ofthe invention is:toprovidea governor of the type under"considerationvwhich,.

due toits design, constructionnand mode Eof.: openation'5 so controls` the engine that-fthe latter-rin lconnection with abrupt. orpronounced accelera?,-

tionordeceleration^is quickly brought :back to its pred'eterminedspeedwithoutsanyssofcalledI nuntf ing action.

A Afurther object'of the invention isfto provide Other objects 1 of the' invention andfthe various advantages andi characteristics; of.' the-present governor will be Aapparenti.from arnconsideratlon of-"theuiollovrmg detailed description.

i The-invention consists. in the seamerainovel features'awhich arezhereinafter'v seti f0rth.and. are morezparticularly' dened'. by claims at 'thel corr;-

-clusionz hereof.

In` therdrawings whichA accompany: andi iorm'za gpart of: this. specification; or disclosure` andrin 'which like numeralsofv reference denote correspondingj parts .throughout the severalviews a.

, Figurel is a plan view of a governory embody.-

ing" the invention certain parte being; broken 4 en vayl or omitted for illustrative purposes.;y

Figure 2.is a longitudinalsectionrof,theigov- .ernor. taken. on. thev line 2--2- of Eigure.v 1 and illustratinginv detail the construction and. arrangement: of, the various,operating, parts .,of., the 45 governor;

A Figure' is a view.4 of one end. of;V the governor.;

. lFigure, et is a transverse sectiontaken IonL the line 4 4 of Figure 2fand showing in detail'the Figure 5 is a transverse section taken: venti-ie lineA 5.-5. of. Figure y2. and showing/the arrangev.fment` and manner of mountinglof 'the spring.. 'devices for maintaining the 'floating drum-*in as (Chkzk'e-rlfl )r 2:. normal or neutral position with: respect ltint/he Shelli:-

Figurer 6. isf: a\ transverse section` taken. on .the lineE 'iK-4i ofiY FigureZ;

.i 5 Figure: 'Tris' an' enlarged: detail of! one off the springrdevices-,-shown in: Figure 5;

Rigureis` a.; circuit.y diagram. showingfthe switches: whicn are governor. actuated andf'serve to` `control the actuating.y devices of: the con'.-

.iofltrbllable pitch propeller with?. which; the: gov;-

ern'orris.assooiatedgv Figures. 9g 9? andi 9b# are y diagrammatic-1 views sliowvingthe mann'errinwhiohthe operating; parts ofittietgoverrior.` operate: on respond: in connection i5 twit'l-afgradua'l `acceleration fand; deceleration'.l of

the y'propeller drin/inge.` engine;

Figures: 10,'2 y10e;` 10b; 10CV and 10@ are diagram;- matic u views showing-v the#A manner in'v which; the operating`l partsmf:` tires governor' operate or' re.-

gu-s'pond'iirA connection@ with'. abrupt` accelerationr of the enginey and.x

Figure 1l is a graph including. a: theoretical speedior perfomance curve ofithe' governor'oont'rolledl engines. illustratingrthe: manner,l in which 25h-trie gow/innenl sol-.contiolsather engine that.: the latterfim oo nnection'... withi abrupt; accelerationf or deceleration; is guiclelvbroughtf -baclrl to! its--v pre,-

' dterminedispeed; without. hunting:

The governon whichlis: showntini the.A drawings 30 lconstitutese.fthey` preferred4 formt' or embodiment ofathe inventionl Itvis. primarily designed for usev im connection; with.I an: airplane (not: shown) having; 2x1/controllable: pitch propeller, and. a propellerdriving-a` internal combustion. engine (both Minen shown and,v aslhereinafter described, oper.-

a-tes bwvarying.the;` angler of. thelpropeller, blades toicoritrol or govern-fthe. engine sothat., it runs ,atl aspredetermined.- speechV As. itsprimary. or principal; partev the governor; comprises, an. elongatedfhousingt IL, an engine). driven, shaft'y I 3. at one;A endetl the housing, afrotary, magneticmem.- ber- |4 in.thehousing'a shell I5 aroundA the ro.- tary-magnetic member, a o'ating drum I6" in associated. relation. with said rotary magnetic .Lniemben an, axiauysndabie control' shaft lrrI and `anielect`ric pilot.- motor I 8.,

Thehousing I2 consists of a continuous' side wall -I 9J and an endlwallZUat one end of theLside v5/all; The other endlof' the sidewall is provided t with ai continuous outwardly extending f iange'ZI. l"'IleIside and" endwall, of' the housing together denne av chambern 22"inn Whichv substantially all of-tvhe operating-parts' of Vthe governor-are mountiedj" The sidewall ofrjtliegovernor'housing ispro'- .viiie-d zon opposite-:1sidesy thereoff withVA apertured shaft or other coupling (not shown) to one of 31 is of conventional construction and surrounds,- and is loosely mounted on, the control shaft I1. It is disposed in the chamber 22 between the;` gear 33 and the rotary magnetic member I4 and embodies a drive member 4D and a driven member 4|. The planetary gearing 38 surrounds the' central portion of the control shaft I1, as shown in Figure' 2. It is disposed between the overload vclutch 31 and the rotary magnetic member I4 and consists of a ring gear 42, a pair of planetary;

Y pinions 43 and a sun gear 44. The ring gear 42 the driven elements or parts of the engine, such, y

for example, as the cam shaft, in order that the shaft I3 is driven conjointly with the. engine.

The Inner end of the shaft I3 vprojects into the end of the chamber 22 that is adjacent the end wall of the housing I2 and has a pinion 25 xedly connected thereto. Such pinion, as described hereafter, forms part of a gear train 26 for driving the magnetic member I4 from the engine driven shaft I3.

The rotary magnetic member I4 is disposed. in the central portionof the chamber 22 in the housing I2 and is loosely mounted on the central portion of the control shaft I1. The latter eX- tends longitudinally through, and is centrally disposed with respect to, the housing I2 and, as hereafter described, serves, in response to axial shift thereof, to actuate the control devices for the controllable .pitch propeller. The end of the control shaft I1 that is adjacent the end wall 20 of the housing I2 extends through, and is slidably mounted in, a tubular element 21 and has the.

extremity thereof disposed externally of the housing I2 and adjacent the bearing 24 for the engine driven shaft i3. The tubular element 21 is formed as an integral part of the housing end wall 20 and has a key 28 which fits in a groove 29 in the adjacent end of the control shaft I1 and coacts therewith to prevent rotation of the shaft while at the same time permitting the shaft to slide` or shift axially.

The magnetic member I4 comprises an elongated hub 30 and an enlarged cylindrical body 3| at the end of the hub that is remote from the end wall 20 of the housing. It also comprises a metallic bushing 32 in the hub, andan annular series of U-shaped permanent magnets 33 in the cylindrical body 3|. The hub and body of the member I4 are formed of any suitable non-magnetic material. The bushing 32 is fiXedly secured within the hub 30 and surrounds loosely the central portion of the control shaft I1. The magnets 33 are embedded in the cylindrical body 3| of the member I4 and are arranged so that the ends.

thereof extend through the periphery of the body (see Figure 4). The rotary magnetic member |4- is driven from the engine driven shaft I3 by way of the gear train 26 which, as previously pointed out, includes the pinion on the inner end of.

the shaft I3. In addition to the pinion 25 the gear train includes or comprises a gear 34,"a pair of gears 35 and 36, an overload clutch 31, and` planetary gearing 38. The gear 34 meshes with,

and is driven by, the pinion 25 and is rotatably` mounted on a stub shaft 39. The latter is fixed ltary gearing 38.

side wall 41. flange 49 at said one end of the side wall of the is nxedly secured Within an internal annular groove 45 in the central portion of the housing side wall I9 and has internal teeth. The plfanetary pinions 43 of the planetary gearing 38 are in mesh with the internal teeth of the ring geal 42 and are positioned one diametrically opposite the other. They are rotatably mounted on a jpair of stub shafts 4B, and these are connected to diametrically opposite]` portions of the driven member 4| of the overload clutch 31. The-sun gear 44,is disposed between, and mesheswith, the planetary pinions 43. It extends around-land is suitably xedly secured to, the outer or free end of the hub 3|) of the rotary magnetic member I4. The gear train 26 comprising the pinion 25, the gears 34, 35 and 36, the overload clutch-31 and the planetary gearing 38, is preferably such that the planetary pinions 43 of the planetary gearing revolve bodily around the control .shaft |1 at the same speed as the engine with which the'governor is associated. For purposes of the present disclosure it will be assumed that the engine driven shaft I3 is driven by the engine in aclockwise direction as viewed in Figure y3. Because of the arrangement of the various pin-l ,ions and gears of the gear train 26 between the shaft 'I3 and the rotary magnetic member I4 such member will also be driven in a clockwise 4direction and the planetary pinions 43 will revolv bodily in such direction.

.The shell I5 surrounds the rotary magnetic member |4'and is located in the central portion of-fthe housing I2 directly inwards of the plane- It is vcup shaped,V as shown in Figure 2, and comprises a cylindrical side Wall land an end wall 48. The side wall is arranged in concentric .relation with the magnetic member I4 and has at the end thereof that is adjacent the planetary gearing 38 an inwardly extending annular flange 49 which, as shown in Figure 2, is connected by screws 4Ila to the inner ends of the stub shafts 46 for the planetary pinions 43. The end wall 48 of the shell I5 is xedly or rigidly connected to the other end of the cylindrical Because the inwardly extending shell is connected to the stub shafts that serve rotatably to support the planetary pinions 43 the shell |5 rotates at engine speed during drive of the engine with which the governor is associated. In view of the fact that the gear train 26 includes the overload clutch 31 drive of the shaft I3 is permitted even though the shell lI5 yis held or locked against rotation. The overload clutch also ,permits rotation of the shell I5 in the event that I5 andA surrounds the rotary magnetic member A greater diameter thanfthe fperipheryp'fthe' maglla. It .is moseymounted-.femmeaxially sndabie control shaft 2|.1 and vcomprises aieircularatend Such The Wall D and-.apylindrical `side'zwall 25|. -Walls arel formed: of nonemagneticrmaterial.

Ccentral `portion Iof ithe fendi-wall :rillembodies la metallic bushing 52 :and this surrounds .i loosely the central portion of the control f shaft I1 and `permits thefdrum to-rotate relativelytoithe: shaft .and the shaft 'to `move axially :relativelylto nthe drum. The. cylindrical :side `Wall'l l of the tdrum `is 'joined to the outer-marginal portionofithe end wall 50 land extends around -thelcylindrical body/3| of fthe rotary magnetic member .i |14. :The inner periphery oittheA side wall-Sl isy offsligh-tly Inet carrying body 3|- oftheimagn'etic memberld land hasanannularfseries of arcuategrooves 453 Ain-'vvhich areI seated stripsd of ironzor any. suitable material 'that is subject to magnetic in-- fluence. Imaterial having a low `resistanceto'felectric current flow andi the member =I6` drivenby the "eddy currents induced therein or =an induction motor squirrellcage could be builtintoftheinner sur- 'face of the vvvall 5|. When'the'rotarymagnetic` Amember i4 is drivengasithe result of drive of -the renginedriven shaft I3-th'efdrum IBIis driven'as the result offmagnetic forces Whichfare-produced by,V or emanate from, the permanentlmagnets 33 in' thefcylindrical bodySl'of'the member-i4. The

'strips 5ft-are greater Iin number i'thanthe per- -manentfmagnets 33 in-order thatthe dri-ve `of the drum I6 by the-rotary'magnetic memberld Ais continuous -asv distinguished from intermittent.

'The planetary pinions'-4f3=an"d"the -sungear M of theplanetarygearing 38 are soproportioned or of such sizefthat under'normaliOperatingcondisition to one another and, as shown in 'Figure 5,

'are disposed at right-angles to oneanoth'er. =As `shown in Figure '1g-the spring device-55consists vof a thimble 51, a compression sprlngi58 andan adjusting lscrew 59 v'and lcoacts with la pin `(il).

"The thimble '51 is slidably mounted in 'an apertured lug 6| on'the'outer face of the'end'wall 48 of the shell l5 and comprises'a cylindrical side wall S2, an end wall 63 at one end ofthe side Wall, and an outwardly extending'annularflange 64 at the otherend-of the side Wall. The side Wall'has a greater'length than the=thicknesspf .the lug 6l and theflange 84'serves as afstop for limiting sliding movement of the thimble in the direction of the end Wall 63. The compression spring 4518 is arranged so'that one-endthereof-ts *Within the side Wall 62 of the thimble'and abuts against the end Wall 63. The otherend of the spring abuts against the 'adjusting/screw 5'9'Which `is mounted in an internally threaded-aperture'SE in a -lug 66. Such lug is mounted 'onthe end iwall 48 of the shell Eland isfdisposedopposita and in spaced apart relation with 'the`lug v(il.

servesto vary orvadjust'theloading of the com- If 'desiredthe strips 54 y:may be of a .6. wiseofithez governor housing: h2 andihasfoneien Vthereonembedded in'ztheend wallf dftheziloat- Yin-grdrum L16. Theiothfer en'd of .the 1pm extends through La circular hol'ei'61 .in fthe l end waii of the shell t5 :and Lnormally abuts lagainst "the end Wall1l3 ofltheithimblefl Thehole smf 1 materially isgreater v"diameter 'than th'e .pin fiin i orderl 'to .permit turning or :.rotationa'of `the :Ilotf -in'gsdrum lrelatively.tothe'shell Normally the free end.I o'flthe .pini-60; is: inlcenteredlrelationiwith' 'i the hoie and thezfthimble is iniltheapositilon shown vin Figure.7. The spring device 56\.eoacts\with:a :pin158 y,and is .\.the.samesas 'the device55fsofarlas construction and foperation :are rconcerned. It 1 comprises aflthimblel, a vcompression sspring 510- `and anfadjusting screw 1|. Theathimblei'si'carried by, Yand sli'clahly imounted i in, an 1 apertured lug4 Klrorifthe f' outer face of the l' end '.wall 548 fief thershell -and lthe adjusting .screw :1I .flscar- Jriedlby a lug lvvhich is alsomountedeon 'the 'outeri'face ofthe-shellend Wall 482vand is disl- "pose'd inopposed relation Withizthelug 10; '.The :pin 68 iis disposed lin :parallel irelation "with Ethe `pinlla'and has 'one end-thereof erribeddedlintthe 4enduwall` 5510i the i floating :drum z 1:6. Thei'other endcof the .pin T63 extends `through* an enlarged circularhole 1113 in. the shell end .Wall Mend nor- `mall'y* abuts against the end Wall 4 of v:the ithinrble 69. The pin 68 and the hole 14, respectively, corirespondin `'diameter to the pin 60 andthe liolel`61. Because the hole 214 isoftgreater diameter-than =the'\pinf'58.thefdrum is permitted'to:turnaorrotate to-'a limited extent relatively "to theslielll SI5. Normallythelpin 68 fis in centered i relation? with .'thelhole Mand abuts againstthe endwallof thethimbleEl. The twoispring devices '5152and "5'6 ftend; `as previously Epointed out, Ito :maintain Vthev'iirum.in-itslnormal or neutral position with respect to ALthe shell `f l 5. When the Idrum .turns -or rotates in oneldirection relatively to-thefshell yone o'i-the spring devi'cesiiscompressed and'Wh'en the-'drum 'turns or rotateslinthe oppositefdirc- 'tionmelatively to the shellftheother springldevie'e is-'compressed By reason o'f the fact` th'atlth'ev `outerfends-'df the pins lland extend Lacross the end-walls 'of the thirnbles of'thesprin'gfdevices the drumis permitted to move axially ineither direction relatively to the shell. WhenIlthelgovernor'is in operation andith'e engine abruptlyfpr lrapidly accelerates 'or decelerates "the Heating 'drum 16, due tolinertia or momentum,'substan- 'f tially 1 instant'aneouslyv turns relativelylto .theshell -I`5, fthe extent offturning being determined iby 'the-'size of lthe `holes `61 and 14 -and the Faction y'of the spring ='devi'c'es '55 and 5"8. Hou/ever, lin connection with gradual increase ordecreasein speed v'of the |engine f the ldrum AI 6 rotates r-at `the same l"speed 'as the shell andvv is maintained vin its neutral position with respect to fthe shell :bythe spring "devices andl56.

Thefelectric pilot .motor i8 is located 1in op'- posed relation with the engine driven 'shaft il@ and operates through-theme'dium of planetary fgearing`15 to drive a U-shaped member 1li 'fin thevchamber "'22 "in the "housing L |72. 4hAs' shown; lit is 'adirect current motor and comprises a 'casing .T1-and an armature 18. One-endof the motor r'casingis provided with an outwardlyextending annular flange 19 an'dfthis ts'against the fout- Wardly fextending annular vange 27|- on the side ywall 1950i the governor housing and is connected Vtheretoby way-'of A'bolts 80. Ii desired fafsynlchronous :motorniay -be used in tpla'ce'ofth'e ldi- 'rec'tycurrent motor #"8 Vand the 'frequency yo'f *the alternating vcurrent supplied v"thereto lvari'efto ment with the control shaft I1.

serves to supply current vto the pilot motor I8. if One side of the battery is connected to one of the :terminals of the motor by way of a conductor .vided with a switch 84 and a rheostat 85. rheostat serves as a medium for varying or .has vthe shaft I3. operation the governor, as hereinafter described,\

,planetary pinions 89, and a ring gear 90.

.rijn the motor at the desired speed. The armature Jis; rotatably mounted in the casing and is arranged so that the shaft thereof is in axial align- A battery 8| 82 and theother side of the battery is connected -to the other motor terminal by way of a conductor 83. The last -mentioned conductor is pro- The changing the speed of the electric pilot motor `vI8 when the switch 84 is closed. It is of conventional or standard construction and comprises a resistance element 86 and a rotary arm :81. The arm is movable over the resistance ele- '.ment in order that more or less of the resistance element may be cut into, or out of, the circuit .for the pilot motor I8. The armature of the motor is driven in the same direction as the engine driven shaft I3, i. e., in a clockwise direction as viewed from the end of the governor that When the pilot motor is in operates to control the engine so that it runs at a predetermined speed, i. e., a speed which is directly proportional to the speed of the pilot motor.

The planetary gearing is disposed around the inner end of the armature shaft of the pilot motor I8 and comprises a sun gear 88, a pair of The sun gear is in axial alignment with the armature shaft and has an elongated hub 9|, the outer .end of which fits around, and is keyed to, the

inner end of the armature shaft. The inner end of the hub 9| of the sun gear extends loosely around, and serves slidably to support, the ad,-

jacent end of the axially movable control shaft ,I1. The planetary pinions 89 mesh With, and are driven by, the sun gear. They are positioned :one diametrically opposite the other and are carried by a rotatable spider 92. The latter embodies a hub 93 which extends loosely around `the inner end of the elongated hub 9| of the sun gear 88 and is held against axial displacement in one direction by Way of a nut 94 on said inner -end of the sun gear hub. The spider 92 comprises in addition to the hub 93 a pair of radially extending diametric arms and these are provided at their outer ends with shoulder equipped stub shafts 95 which extend lengthwise or longitudinally of the governor housing I2 and serve rotatably to support the planetary pinions 89. The ring gear 98 of the planetary gearing 15 is seated in an annular groove 96 in the end of the governor casing that is provided with the outwardly extending flange 2 I. As shown in Figure 2, the ring gear 98 is clamped against rotation .in the groove 96 by the flange 19 of the pilot -motor casing and has internal teeth which mesh with the planetary pinions 89. When the pilot motor I8 is in operation with the armature shaft thereof revolving in the same direction as the rotarylmagnetic member I4, the drum I6 and the -shell I5, the sun gear 88 drives the planetary rotate the member 16 is disposed between and in paral- `lel relation with the spider 92 and the shell endv flO Wall 48 and has a central hole through which the adjacent end of the control shaft I1 extends loosely. An inner collar |88 and an kouter collar |8| arexedly mounted on the control shaft I1 in straddled relation with the central portion of the intermediate part 91 of the U-shaped mem ber 16 and form a connection between the U- shaped member and the control shaft whereby the I U-shaped member isr permitted to rotate freely around the control shaft while at the same time the member and control shaft are connected together for conjoint sliding movement in either direction lengthwise of the governor housing.

VThe pinsA 99 extend longitudinally of the governor housing and have the outer ends thereof secured to the inner ends of the stub shafts 95 for rotatably supporting the planetary pinions 88 of the planetary gearing 15. The other or inner ends of the pins 99 extend loosely through holes |82 in the end portions of the intermediate part of the U-shaped member 16. When the planetary gearing 15 is driven by the pilot motor |8 the pins 99 operate to rotate the U-shaped member 16. Because the pins 99 fit loosely in the holes |82 the `U-shaped member together with the control shaft I1 is permitted to shift bodily to and from the spider 92. The arms 98 of the U-shaped member 18 are connected to the ends of the intermediate part 91 and project towards, and in overlying relation with, the floating drum I6. control shaft I1 and extend through a pair of diametrically opposite arcuate slots |83 in the end wall 48 of the shell I5. The free ends of the arms 98 are disposed over the inner end of the side Wall of the floating drum I6 and have inwardly extending pin type cam followers |84 which t, respectively, in a pair of diagonal cam grooves |85 in a metallic ring |86. The ring extends around, and is flxedly` secured to, the outer periphery of the cylindrical side Wall 5| of the floating drum I6. The cam grooves are disposed diametrically opposite one another and are arranged so that the leading ends thereof extend towards the U-shaped member 16 and their trailing ends extend away from the member. When the U-shaped member 16 is driven by the spider 92 of the planetary gearing 15 at the same rate of speed as the floating drum I6 the control shaft I1 is held in a neutral position, the arms 98 of the U-shaped member are disposed in the central portions of the arcuate slots |83 and the pin type cam followers |84 are disposed in the central portions of the cam grooves |85. In the event that the drum I6 increases or decreases Vin speed relatively to the fixed driving speed of the U-shaped member 16, due to gradual increase or decrease in the speed of the engine with which the governor is associated, the cam grooves |85 will coact with the pin type cam followers |84 and shift the U-shaped member and control -shaftl axially, the direction of axial shift being vally increases in speed the floating drum I8,

which under normal decreases or increases of speed, is driven at the same rate of speed as the `shell I5, over-runs the motor driven U-shaped .member 16 with the result that the trailing ends ofthe cam grooves I'85 move into contact with They are located on opposite sides of the' arterie fis; associated graduallydecrease in speed ngzdrum ,lswill under-mmthe con- -ven Uqshaped member lwith the restantly.

sliltnthat the leading ends .OfLthe camferooves'l will more; into-engagement with tnerpin type. cam followers/:|04 and cause then-.shaped member 16 1. together -with the control shaftA I 1 to move axially away fromztheengineadriven shaftl. 1As hereine aftervdescribedf axial shift 4of fthe controlshaft I 1 serves-to control the ,controllable pitch Apropeller so that :it intm'nincreases ordecreases the .pitch onattack .angles y.of the. propeler bladesf toreturn thesmotorto the speed that :is set up or established by thepilot motorgl. .The cam grooves I'05,.as shown in Figure l. are but slightlyangled with-the result-that.i the `axial throw of the control-:shaft I 1. .-isbut slight ,when the cantgrooves arelbrought 4into play as the result `of overrunning -or-.yunder-running of e the 'iloating drum I5 withrespect to the motor driven U-shapedmember 16. The arcuate slots |03 in the endwall 08 of-ethe -shell t5 permit limited turning of the oaftingadruand ineitheiwndirection with respect to-the U-shaped member 16. The cam grooves |051; and thepirriftype loam .followers I I 04 y. come yinto play ror-coaet to effectf:limited axialshitof the controlrehaftvw-hen theifloating drumfl Bis turning or-frotatingrconointly with the. shell I5.. and the drum over-'runs-ioriundererunsthe speedofdrive ottthe tuffshapedememberilasithe result of gradual vincrease for ldecrease in the speed .f 4oi I the engine.

.'@As 1,heretofore pointedaoutfthe :floating- :drum 156,5 @because of -inertia.. or-momentum,VV .turns to a limitedxtentwith;respect to the shell in the event-ry that-ftheeenginespronouncedly or abruptly Aaecelerates.or decelerates: 11n order-ltoeffect substantially-instantaneous.axial shi-ft of the; control shaft': 1 anderesultantouick governing or control of the eng-inetin yconnectionwith 1 turning .of the floating drum Ifrelativelyvto -theishell ISa-cam arrangementtin'thehform=cfa pair-of A.pin type camrffollowerssll fand a .pair of camgrooves |08 isv provided. '.The'pin'type scam followers I 01 are ifxedtolandexten'd .inwardly from,I the. sidewall lhettheshell#I5J andrareidisposed adjacentl the pinitypes'camifollowers |04- andl one fdiametrically oppositeuthe other. iThelcam grooves '|08 l are formed.ln:the metallic.'I ring |06 i around vthe outer peripl-ieryoffthegsideH wall' 5 I- of theffiloating drum Brand-rare :arranged ,in-side by side relation With thea camgroovesal'. ":They extend diagonally at armere-abrupteanglegthan @the cam grooves. -I 05 andrare'arranged; sowthatftheleadingf ends thereof extendr .towards the Uf-shaped memberrl i and 'thin'ltraililngrendsrextend/away from said member.' Theelengthtofcthe;cam-grooveso|08 is such thatftheendsofosuch grooves are. laterally offset to ,the same extent-fas -theendscfrthe-'cam grooves M5. ":FIihe pi'n wtypefcamrfollowers1.-.I01are arranged so thatethe endsf1 thereofproj-ect into the cam groovesrliUB-and-are so positioned: that when thefoatingdmmefl i'saheldfin VAits.nor1nal or neutrial pesitiontwith'frespecttotheshelld 5 vas Athe reuiftif the actoniofithe:splirlgrdevices: and 56 their inner ends are disposed in the central por-l tionscissaidcam?grmresfls. finsscrningrhat the .ellnetirren shafts! 3 ,s.gelaat-ingzfinl` a :clockwise .directieraad regierenenitlrawhch.:tb @governor is Delaware/brandy@accelerates cri-,any rea- 19 rrhatsererssecb; in eramplerasimaymccur is designed foruse.

in-I the. event that the airplane is placed into a steep dive, the shell I 5 will, because of the inertia of the floating drum I0, rotate in a clockwise direction-relatively to the drum with the result that the pin type cam followers |01 will slide along the leading ends of the cam grooves |08. Such sliding movement on the part of the cam followers |08 will cause the floating vdrum to move or slide bodily in the direction of the engine driven shaft I3, fand effect corresponding axial shift of the control yshaft I1. Shift of the floating drum towards the shaft I3 results in corresponding axial-shift-of'the control shaft I1 by reason of the fact that Vthe iloating drum is operatively connected Ato the control shaft through the medium of the l-J-shaped member 16. In connection .with initial abrupt acceleration ofthe engine-the shell I5 over-runs the floating Adrum I5 andthe drumadvances slightly with respect to the-U-shaped member 10 with the result that both cam arrangements are broughtA into play and the control shaft I1 is shifted axially toward the engine driven shaft I3 a greater distance than itwould be shifted if only the cam arrangement in the form ofthe pin type cam followers |04 and the cam grooves |05 Were brought into play. In the event that the engine with which the governor is associated abruptly deceleratessuch, for example, as may occur when ,theairplane is placed ina steep or high climbing. attitude, the oating drum I E, becauseof its momentum, over-runs the shell I5 to thev extent permitted by the pins 60 andl in their respective holes 61 andld withthe result that the trailing ends of the diagonallyfdisy posed cam grooves |08 slide into engagement with the inner ends of the pin type cam followers |01. Because of the angular arrangement of the trailing ends of the cam grooves |00 such endscoact with the cam followers |01 in such manner as to shift the noating drum I5 toward the pilot motor I8 and effectcorresponding shift of the control shaft I1. Such corresponding shift of the control shaft I1 is attributable to the fact that the lloating drum is operatively connected toy the control shaft through the medium of tne- U-shaped member 16, In connection with initial abrupt deceleration of the engine the shell I5 under-runs thelloating drum I0 and the drum lags or is angularly displaced to a slight extent with respect to the U-shaped member 16 and hence both cam arrangements are brought into play and the control shaft I1 is axially displaced in the direction of the pilot motor to a greater extent than is-the case where the cam arrangement in the form of the cam type followers |04 and the cam grooves |05 is brought into playfdue to gradual deceleration of the engine withvrespect to the pilot motor I8.

As previously .pointed out, the governoris adapted tofcontrol or -govern the speed of the airplane engine with which it is associated'by varying vthe angle of the propeller blades of the controllable pitch propeller. :The controllable pitch'propeller which is disclosed in, and'forms lthe subject matter of, an application for United States patent filed by Archibald (n-.Forsyth .on August 12, 1943, vSerial No. 498,367, now. abancloned, represents one form or type of controllable pitchpropeller'with which the presentgovernor Such controllable pitch propeller includes in `addition to a hub' .and axially rotatable -blades on" the hub, pitch change mech--` anism including a magnetic clutch `type Adevice. for effecting increasein Ithe pitch 'of the propeller blades. at. a-slow rategga-magnetic clutch .type

1l device for effecting decrease in the pitch of the propeller blades at a slow rate, a. magnetic clutch type device for effecting increase in pitch ofthe propeller blades at a fast rate, and a magnetic clutch type device for effecting decrease in pitch of the propeller blades at a fast rate. Such devices are diagrammatically illustrated in Filsr` ure 8 of the drawings and are designated, re` spectivelv, by the reference numerals 09, H0, III and I I2. These four devices are controlled, respectively by norm-ally vopen push button switches H3, H4, H and H6. Such switches are mounted on a bracket II'I on the exterior Y of the governor housing l2 and adjacent the engine driven shaft I3 and, as hereinafter described, are controlled automatically in response to axial shift of the control shaft I'I. The )bracket HI is bolted to a lug H8 on the side wall 'I9 of the governor housing and overhangs the end of the control shaft that projects through the end wall 20 of the governor housing. The switches H3 and H4 are mounted one directly opposite the other on the bracket II'I and are arranged so that the buttons therefor face or oppose one anotherV and are spaced apart but a small distance. The switches H5 and H6 are mounted on the bracket II'I to one side of the switches I I3 and H4, respectively, and are arranged so that their buttons face one -another and are spaced apart a distance greater than the distance between the buttons for -said switches H3 and H4. An upstanding arm H9 forms an operating connection between the switches and the end of the control shaft I'I that extends through the end wall 20 of the gov-` ernor housing. The lower endof the arm is provided with a hole |20 and is iixedly or rigidly secured to the exposed end of the control shaft I'I by way of a bolt or cap screw I2| whichextends through ther hole |20 and into an internally threaded socket in the exposed end of the control shaft. The other or upper end of the arm is provided with an elongated crosspiece I 22, one end of which extends between the buttons for the switches H3 and H4 and the other end of which extends between the buttons for the switches H5 and H6. Closing of the switch I I3 results in closing of the hereinafter described circuit for the device |09 and results in the pro-` peller blades being increased in pitch at a slow rate and the engine correspondingly decreasing in speed. When the control shaft I'I is shifted axially to a limited extent in the direction of the engine driven shaft I3 as the result of the cam arrangement in the form of the pin type cam followers |04 and the cam grooves |05 being brought into play because of a gradual increase in speed of the engine over the fixed or set speed of the U-shaped member 'IB the arm moves away from the governor housing 'and elects closing of the push button switchA H3 for the slow rate increase pitch device I 09.` When the control shaft I'I is shifted axially to a limited extent in the opposite direction, i. e.,` l

Closing of suchv switch' H4 completes "the here"` inafter described circuit'for the device'HD and results in the propeller blades being' decreased in pitch at a slow'rate and a correspondingin-A crease in speed of the engine. When the control shaft I'I is shifted `axially in the direction of the engine driven shaft I3 to a greater extent as the result of both cam arrangements being "broughtinto play due to initial abrupt increase in speed of the engine the arm I9 is movedaway from the governor housing I2 and causes closing of the switch H5lfor the fast rate increase pitch device III. Closing of the switch' H5 completes the circuit for the device IHA 'and iresults in the propeller blades being increased in pitch at a -fast rate. When the control' shaft Il is `shifted away from the engine driven shaft I3 as the result of both cam arrangements fbeing. brought into play due to initial abrupt decrease in speed of the engine the arm H9 moves towards the governor housing andv effectsclcsing of the switch H6 for the fast rate decrease pitch device H2. `Closing of the switch H6 `completes the hereinafter described circuit for the device H2 and resultsin a fast rate decrease in pitch of the propeller blades. Due to automatic vrcontrol of the' switches by the governor `the Lengine is governed so that it maintains a predetermined speed corresponding to the speed of drive ofthe U-shaped member T16. l The circuit for the slow rate decrease pitch device H0 comprises a battery |23, a conductor |24 leading from one side of the battery to one terminal of the device H0, a conductor |`25`.-lead ing from the other terminal ofthe device H0 to one contact of a normally closed switch |26, a conductor I2'I leading from the other contact of the switch |26 to one contact of the fpush button H4, and a conductor |28 leading from the other contact of the switch H4 to the other side of the battery. When the switch I I4 is closed, as `hereinbefore described, the aforementioned circuit is closed with the result that the device II'0 decreases the pitch of the propellers at a slow rate andlcausesthe 4engine to accelerateor increase in speed. As soon as the engine accelerates tothe same speed .as the speed of the U-shaped member I6 the control shaft I'l-is automatically shifted to its neutral position thereby resulting in opening of the switch I I4.

The circuit for the slow rate increase pitch de.- vice |09 includes the battery |23 and comprises a conductor |29. leading from the conductor-|24 to one contact of the push button switch H3, a conductor |30 leading fromV the othercontact of the switch H3 to one contact of a normally closed switch I3I, a conductor |`32 leading from the other contact of the switch I3| to one terminal of the slow rate increase pitch device, |09, and a conductor |33 leading from the other ter minal of the device |09 tothe conductor |28. When the switch II 3 is automaticallyclosed as the result of the engine gradually accelerating or over-speeding the` aforementioned circuit ,is completed with the result that the Adevice I 09 causes a slow rate increase in pitch of the pro peller blades andthe engine decreases in speed; As soon as the engine decreases in speed tothe speed of the U.-shaped member 'I6 which, as hereinbefore pointed out,r is rotated or vdriven at a constant speed by the pilot motor I8, the control shaft I'I is automatically shiftedinto its normal or neutral position and the switch H3 opens, thus breaking the circuit for the device The circuit for the fast rate decreaisepitchgde# vice H2 comprises a conductor v|34 leading from the conductor |24 to one terminal of; the device I I2,` a conductor |35"leading' fromthe-.other terminal of the device H2 to one contact'of the :gesamte 13 switch II\6, andar conductor lIftllv'eadin'gr` fruxn'rthe other contact fof 'the a switch EI' t6 dofthe :conductor |28. 'As :shown Sin .Figure f8, therfconductor |35 includes :a-fsolenoid L31 :.whichis `ic'meratively@connected 4Sto the :switch 'I'IG'in thefcircuit :for the slow frate 'idecreaselpitchidevice I1t0s:and- :senves when the I'circuit for the device sllmis @iclosedf as the :result `of Aclosing Iof -the :switch I t6,` "to uopen the switch I 26 and lbreakr theafcircuit "'for'rthefdevice IIO. "When'thefswitch .IIiIBriiscclosed asrthe result of the tengine :abruptly uiider-speedin'g-fcr dcceleratingy the -fcircuit' vthrcug'h itheil'device 2'I.I 2

blades-aredecrea'sedn pitch 2.a ifas'tnate." soon-as the-.fengine -v-speeds :.up' thefspeedffdetermined by the milo'ttrm'otor .flaclthecontrolxhaft I 'I will 4.have iheen xshif ted to its meutral rposition and thevswitches I I4 :and I ISE-.ftherby lopened and effecting an l@opening :of "Sthe .ccircuit'for title devices -lI I`01and'1II'2. ".Il'iesolenoidY I'lffor `operiing the switch 1I 26 -is included .iniithe fcii'cuitffoithe 4ff'ast rate fdecrease mitch-device i2.: hereiribe'fore described. viPrcnounced..fshiit Aof fthe control sha'ft |12'towards the pilot #motoilinrconnection with lnitiahabrubt l"decelera'ticnnor funderspeeding or the enginecauses ftheicrosspiece |22 of thearm lIIS .tofclosefthefsWitch |114 @before fit closes l:the switch H5. iHowever.,:-asxs'oonrasf the switch III6 is closed thelcircuitf-forthe s'lowrat'e decrease pitch .deviee I-.Ig0 yis fautomaticllyscpened as the-resultof the'actionoffthe 'solenoidfwheven though the r switch .Ifl 4e is held y:i-nflit'sclosed position byfthecrosspiece 122.

vThe fcircutfifor ysthe fast ,irate increase-mitch device 1I Il includes .fthe fbatterytz and-'comprises f a lconductor [38 :,.l'eading lirom 'sithe Iconductor I'Z to one contact of the switch ,Iltyfa conductor 4:39 leading:` from the :other :contact cf :the switch Y'I I5 `to :onerterminal c'fL th-ef'devce I I I and .a` conductor M0 leading 'fromitha other terminal :of "thesd'evice 1| II `to 'the rconductorfil. The l conductor I'3'9 includes?asolenoid-l I 4I which is :operatively :connected 4itc ifm'allyfclosed crease pitch device I09vandtserves when-*the 'cirhave fautomaticallysliited 4'to dts ineutral Lposition, resulting .in opening fof it'he#switcltfes II'3:fand-"FISI5. The :solenoid ISM iis included finthed'zircitffoi'I-'the device III because whenthe farm 3IUI"`9 lvis Jino've'd away' i f rom the-governor 4fhous'ing.y fin irconixection with initial fabruptfaccel'eraltionfor 'over-"speeding of-the I'ez'rgii'xe fthe L"switch I ID3 `is closed LLbefore `vthe switch :I I5 and 'i it is 'lh'ende necessary to fhialk' "0r (ifi tion 'Winti-respect itothe-fshell -15 #androtates :con-1 ointly -with such-.shell 'and .the .control shaft IJI` is 1in 'itsl'neutral position lwherein'it maintains lthe arm It91in1f-arpo'sition whereinthe crosspiece .|22 th'ere'ofsis out-'of vcontact withany ofithepushbuttonfswitcheslil, 'I I4,I.I5 and II0. So longlasthe speed fo'the enginef'correspon'ds tothezsp'eedipredetermined fby the -pilot motor I8 the pin :type camflloweisllllleare disposed in the'cen-tralportion "o' theicarnf'slots 105 andthe vpin type :cam followers' |071 :areidisposed in the vcentral `portion cfthe-.camsmt's Ilgas shown in Figure 9. In the event fthat lthe fengine gradually increases in'A speeiiio'rJ ahy-reason .whatsoever .the 'floating druifrlwwhi'ch inhconn-ec-tion with gradual engine acceleration :is :turned vor rotated conjointly with the shellfIS, over-runs'the pilot motor driven U.

shapedmiember '16 with the result that the pin type'ca'm"followers v-I 04 .mfev-e into the trailing ends of the 'earn-slotsH05,- a'sshcwn in Figure 9a. Suchrno'veinent:Lonthezpart of the-cam followers I0'4 causeisftheU-fs'haped member 'l5 and the'icontrol shaft TI 1 :toxmove a flimited extent in vthe `direction oi theengine-fdriven shaft I3. Shiitfof the shaft I-I tofa limited extent 4towards"theengin'e driven shaft Iir'resultsin closing-or 'the switch IiI3`- and this `finiturri causes factuation of the slow rate increase lpit'ch 'device l09. Immediately upony a-c-L tuationfcfvsuchidevice the propeller'blades are increasedfinpitch at a slow rate 'with the result that'ftfh'e engine `slows vdown or decelerates. soon fafsthelengine decelerates or slows down" to the :pre determined Ispeedfthe'pin 'type cam follow; ers T04 move intothecentralportions of the cam grooves |05 and result in the rU--sh'ap-edrnemloe'r I6 "and Athe f control z shaft 'I I lmoving :towards-- the pilot .motor 'IIB 'ntotheirneutral positionand re-,. sultaut `lripening `oi the Yswitch I I3 for the slow rat-'e in'creasepit-ch device IDQ. fIn'theieVent .that the=eigine :gradually ydecreaseslin `speed for any reasoniwhaftsoever the floating drum I 6 which in connection with -gradualdeceleration Iof the engineiotat'as'coiijointly*with the shell I5,'under sneedswtfhepilot motor'driven member 'IS with the' resiiltvtli'at T'fthepin'type `cam followers `H14 move intoathe `leading ends of :the :cam slots |05, as shown zin'l'igure 9h. fAs 'the cam followers `I04 move into the vlead-ing vends of the 'cam slots' |05 they-c'ausethepilot motor driven`U-s'haped-mem-- ite'dextent inithedirection of'the pilot motor I"8.

Limited-shift of'thecontrol shaft in the direction o'ffthelpilot=motoricausesfthe arm I'I9 tov close the switch -I'I'4s'and Aresults in actuation of the slow ratedecreas'efpitch device IIO. Immediatelyiupon actuation o'f Isuch 'device 'the fpropeller vblades fare decreasedin =p`itch at'a slow rate =with`the result thatithe enginein'creases inspeed until'it reaches' its predetermined or governed speed. At :such

centraliportions of the cam slots |505 fand retract the 'U--shaped-member :'landfth'e control shaft -IlIf te"1 h'irhelitrallpnsit'ion. "Reti-'action 'of the'con'- trol-1sha`fteresults iin fope'ning 'of Ethe switch vI ITI.' Because o'f th'ehigh'sensitivity-'of thegovernorithe' engine lwill return yto 'Tits Apredetermined speeddi' rectlyfafter gradual acceleration or rdeceleration` thereof.

In the =event th at the vengine should/abruptly acl celerat'eias the lresultfo'f the airp'lanebeing'placed ina steep# or sharp divethe operation of the l"gov ern'or'is'as-'follows V At the initial ypartfof abrupt "acceleration of th-@engine *the foating drum il E slig"htlyfovelf-:runs the fp'ilo't motor 4driven U-shaped member ".10

andthe shell I5 over-runs the drum, thus bringing into play both cam arrangements. As shown in Figure 1()a over-running of the drum with respect to the member 'I6 results in the pin type cam followers |04 moving into the trailing ends of the cam grooves |05 and the pin type cam followers |01 moving into the leading ends of the cam grooves |08. Movement of the cam followers |05 linto the `trailing ends of the cam grooves |05 combined with movement of the cam followers l|'| into the leading ends of the cam grooves |08 and resultant shift of the floating drurn I6 in the dire'ction` of the engine driven shaft I3 results in the control shaft Il being shifted to its full extent in the ldirection of the shaft I3 and consequent closing of the push button switch I I for the fast rate increase pitch device |II. As soon as the switch I I 5 closes the device I I I increases Ithe pitch of the propeller blades at a fast rate. As soon as there is no increase in the rate of acceleration of the engine las the result of increase in pitch ofthe blades at a fast rate the floating drum I6 vis returned to its neutral position with respect to the shell I5, as shown in Figure b. This is due to the faction of -one of the spring devices 55 and 55 and occurs at a point near the peak of acceleration of the engine. When the drum is returned to its neutral position with respect to the shell as the result of spring action the pin .type cam followers I0I move into the central portions of the cam grooves |08 and shift .the iioating drum towards the pilot motor I8 to its neutral position. Shift of the drum to such position effects correspon-ding shift of the control shaft Il and result.- ant opening of the switch |I5 for the fast rate increase pitch device III. In view of the fact that the -engine at the peak of its acceleration is over-running the pilot motor I8 the cam arrangement in .the form of the cam followers |04 and the cam grooves |05 remains active to the extent that it serves to retain closed the switch |I3 for the slow rate increase pitch device 09. After the engine reaches its peak of acceleration it starts abruptly to decelerate. During deceleration of the engine before the engine reaches its predetermined speed as set or determined by the pilotl motor I8 the floating drum I6, because of its momentum, over-runs the shell I5 and causes the pin type cam followers I0I to move into the trailing ends of the cam grooves |08, as shown in Figure 10. As the result of the cam followers |01 moving into the trailing ends of the cam grooves |08 the floating drum is shifted from its neutral position toward the pilot motor IB and returns the control shaft I'I to its neutral position` even though the pin type cam followers |04 remain in the trailing ends of the cam grooves |05. As soon as the control shaft is moved into its neutral position as the result of under-speeding of the shell with respect to the drum the switch I I3 for the slow rate increase pitch device |59 opens and the governor is in a satisfied or no-governing condition. Such condition occurs prior to the engine dropping in speed to its predetermined speed. After the governor is placed in its n0- governing position as heretofore pointed out, the engine, due to momentum of its parts, coasts down to its predetermined speed. During coasting of the engine to its predetermined speed one of the spring devices 55 and 56 returns the floatingdrum IBto its neutral position with respect totheV shell I5 and the pin type cam followers I 04 Vniove yin-to the central portions of the camr grooves y |05. Thus when the engine i-n connection with coasting thereof reaches its predetermined speed the governor is in :immo-governing orvneutral position.; and hunting is thus eliminated. The pointat. which :the governor assumes Y'its no-governin'g position or condition prior to the levelling oif of the engine toits predetermined speed depends upon the degree of abruptness of acceleration. If the magnitude of abruptness of acceleration is great then the governor will. assume its non'- governing condition in connection with deceleration of the engine quite a bit ahead of the engine decelerating toits predeterminedspeed. lf the degree 'of abruptness of engine acceleration is cornparatively Small then the governor assumes its no-governing position at a pointdirectly in advanceof the engine due to its momentum-level-l lingoff to the predetermined speed, i. e., the speed determined orfixed by the pilot motor I8.v By automaticallyarranging for the governor to assume a satisfied or no-governing -condition in advance of the engine reaching its predetermined speed after abrupt' acceleration the engine will automatically level 'ioif to its predetermined Speed with substantially-,no hunting;l In other words, the arrangementfof the governor is such that in connection with pronouncedY acceleration lof the engine'for any reason whatsoever the switches for the `increase pitch devices are opened ahead of the time when'the engine levels 01T' to its predeterminedspeed;thuscompensating for the momentum effect of the engine which would normally cause-the-engine toypass its predetermined speed and-resultant-hunting under; governor control. The compensatingoranticipating feature of 'the present governor is entirely automatic and self-adjusting,` depending upon the magnitude of abrupt acceleration'or deceleration of the engine. vf. i; 'Y r I-nthe event that the engine should abruptly deceleratev as the result of the airplane being placed in`an extremely high climbing attitude the governor :operates in the saine manner as it does in 'connection with abruptl acceleration vexcept that 'thefoperating parts move reversely and the slow rate decrease pitch'device I'I0 and the fast rate decrease'pitch device |I2-are brought into play instead'ofthe slow rate increase device |09 and the fast rrate increase pitch device III. connection with abrupt deceleration of the engine the governor automatically assumes its nongoverning or neutral condition prior to the enginereturning to its-predetermined speed. "As soon as the governor cuts out or assumes its nogoverning position the engine, due to the inertiagofthe parts thereof, levels off or coasts to the predetermined speed and' hence hunting of the engineV is'eliminated in connection with return of the engine to its predetermined speed, i; e., the speed that is'governed or controlled by the speed of-drive-of the pilot motor I8. `f

. :By increasing or decreasing the speed of the pilotmotor I8 through the medium' of the rheo-l stat the Aengine will be governed so as to run at an increased or decreased predetermined speed. In other words, when it is desired to increase the speedh of the engine to any desired R. P. M. the rheostat is adjusted so as to decrease the amount of resistance 86 in the motor circuit. If it is desired to decrease the speed of the engine the pilot motor. is slowed down by manipulation of the rheostat sol as to increase the amount of resistance in the motor circuit. By adjusting the rheostat the. engine .will becontrolled automatically by the governor so that it operates at any desired predetermined speed. It is contemplated that the engine vwill be started before closing ofthe switch 84 in the circuit for the pilot motor i8. When the engine is started while the pilot motor is at rest the overload clutch 37 provides the necessary slippage. After starting of the motor the rheostat is adjusted to the desired point and the switch 84 is closed. As soon asvthe pilot motor is energized as the result of closing of the switch Se the governor operates' in the manner heretofore described automatically to maintain the engine at a predetermined speed. Because the engine after abrupt acceleration tends to return under geverno'r control to the predetermined speed at a different rate of speed than it returns to its predetermined speed after abrupt deceleration the spring of one of the spring devices 55 and 56 is loaded to a greater extent than the spring of the other device. By properly adjusting the loading of the springs of such devices the governor may be set so as to eliminate the tendency of the engine to over-run the predetermined speed in connection with return after abrupt acceleration yor deceleration.

'.f'he graph constituting Figure l1 includes a curve A. Such curve is 'a theoretical performance curve of the engine as controlled or governed by the subject governor. Part a of the curve represents the speed charcteristics of the governor controlled Aengine in connection with gradual acceleration `and deceleration of the engine. As heretoforepointed out in connection with either` a gradual acceleration 'or deceleration of the engine. only the cam arrangement in the form of the `pin type' cam followers IM and the Cain grooves it is brought into play. Part a1 of the curve represents the 'speed characteristics of the engine in connection with an extremely abrupt acceleration of the engine., During pronouncedlyl abrupt acceleration of the engine the engine, as shown by part al 4of the performance curve, rapidly accelerates and during rapid acceleration the operating parts of the governor are in the position shown diagrammatically in Figure 10e of the drawings. In such position of the 'governor parte the switch H5 for the fast rate increase pitch device ill is maintained closed and the blades of the propeller are increased in pitch at a fast rate. When the engine reaches its peak of acceleration in connection with abrupt acceleration as occurs in connection with a sharp dive of the airplane the operating parts of the governor are in the position shown diagranimatically in Figure 10"J of the drawings. In such position of the governor operating parts the noating drum it is in its normal or neutral position with respect to the shell l5 due to the action of the spring device and only the cam arrangement in the form of the cam followers Mld and the cam grooves |05 is in play or operation. As heretofore pointed out, when such cam arrangement is effective the switch H3 for the slow rate increase pitch device i239 is closed and the propeller blades are increased at a slow rate. During rapid deceleration of the engine due to increase in blade angles after pronouncedly abrupt acceleration, the governor cuts out or assumes its rio-governing position at approximately the point :r on the part a1 of the performance curve A. When the point :c is reached the operating parts of the governor, due to under-running of' the shell i5 with respect to the oating drum I6, are in the position shown dagrammatically in Figure c. After the point is reached and the governor is in its cut out or nti-governing position the engine, due to its momentum, slows down or levels off to its pre- 181 determined speed. During levelling off of the engine to its predetermined speed the operating parts of the governor return to their neutral position as shown diagrammatically in Figure 10d. Thus, asshown by part a1 of the performance curve A in the graph constituting Figure ll, the operating parts of the governor are in their neutral position when the speed of the engine levels off to its-predetermined speed. Part a2 of the pe1'fo1''niancev curve represents the speed characteristics of the engine in connection with less abrupt acceleration.' As shown by part a2 of the curve the governor cuts out or assumes its no-governing position at the point .r1 which is nearer the predetermined speed than the point m which, 'as heretofore pointed out, is where the governor cuts out after pronounced acceleration of the engine. In connection with a less pronounced abrupt acceleration of the engine the governor cuts out or assumes its no-governing condition at a ypeint nearer the predetermined speed due to the fact that deceleration of the engine after the engine reaches the peak of its acceleration is more gradual and hence the shell i5' does not over-run the floating drum i6 until a poin'tfnear the predetermined speed. As described heretofore the cutting out of the governor before the engine returns to its predetermined speed is automatic and is self-adjusting, depending entirely upon the magnitude or rate of acceleration of the engine over its predetermined speed. Part a3 of the curve A represents the speed characteristics of the engine in connection with abrupt deceleration due to the airplane with which the governor control engine is associated being placed in a steep climbing attitude.

The herein described governor is highly efficient in operation and effectively and emciently fulfills its 'intended purpose. Its design and construction are suchithat the tendency of the engine, with which the .governor is used, to hunt in connection with governor control, is reduced to a minimum. In other words the governor is so designed and arranged that when the engine acceleration or deceleration ceases under governor control the `engine will be operating at the desired or predetermined R. P. M.

Whereas the governor has been described as being particularly designed for use in connection with an airplane engine and as controlling the engine through the medium of a controllable pitch propeller it is to be understood that it may be used for other purposes and in other capacities. It is also to be understood that the invention is not to be restricted to the details set forth since these may be modied within the scope of the appended claims Without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

l. A governor adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means for connecting it for drive by one of the operating parts of the engine, a second rotary member provided With means for driving it at a contant predetermined speed, a movably mounted speed control element, means automatically operative when the rst mentioned member is driven at a speed different from the second mentioned member due to gradual acceleration or deceleration to move the element to a limited extent, and cam means operative automatically and substantially instantaneously when the first mentioned member is speed control means, a second speed control means, a rotary part provided with means for connecting it for drive by the engine, a rotatably and slidably mounted element responsive to magnetic influence and disposed adjacent said part,V

a magnetic mmeber adjacent the element provided with mean-s for connecting it for drive by the engine and adapted when the engine is driven at its predetermined speed or gradually accelerates or decelerates from its predetermined speed to drive the element at the same speed as the part, said element being adapted when slid to actuate the second speed control means and being further adapted in connection with abrupt acceleration of the engine to underrun the part and in connection with abrupt deceleration of the engine to overrun the part, cam means between the part and the element adapted to slide the element in connectionr with under-running and over-running of said element with respect to the part, a second member provided with means for driving it at a constant speed, and means operative when the element is `driven at a different speed from the second member due to gradual i acceleration or deceleration of the engine to actuate the first speed control means.

3. A mechanical governor adapted to maintain an engine at a predetermined speed and comprising a rst speed control means, a second speed control means, a rotary part provided with means for connecting it for drive by the engine, a rotatably and slidably mounted element adjacent said part adapted when slidto actuate the second speed control means and provided with driving.

means therefor whereby it rotates'at the same l speed as the part when the engine i-s running at its predetermined speedor gradually accelerates or decelerates from its predetermined speed, underruns the part in connection with abrupt ac-celeration of the engine and overruns the part 20 in connection with abrupt deceleration of the engine, cam means between the part and the element adapted to slide the element in connection with under or over-running of said element with respect to the part, a rotary member positioned in associated relation with the part and element and provided with a pilot motor for driving it at a constant speed, and cam means operative when the element is driven at a speed different from the member due to gradualacceleration or deceleration of the engine from its predetermined speed to actuate the first speed control means.

IRA J. SNADER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 683,688 Hollingsworth Oct. 1, 1901 821,286 Grant May 22, 1906 959,853 Grant May 31, 1910 1,130,659 Baldwin Mar. 2, 1915 1,507,356 Horton Sept. 2, 1924 1,509,695 Volet Sept. 23, 1924 1,936,566 Davenport Nov. 21, 1933 2,117,891 Kalin May 17, 1938 2,213,358 Berges Sept. 3, 1940 2,257,126 Rindfleisch Sept. 30, 1941 2,271,629 Couch Feb. 3, 1942 2,293,912 Mullen Aug. 25, 1942 2,302,042 Martin Nov. 17, 1942 2,334,967 Thomas Nov. 23, 1943 2,370,675 McCoy Mar. 6, 1945 2,378,580 Prause June 19, 1945 2,378,938 McCoy June 26, 1945 2,391,323 Martin Dec. 18, 1945 2,399,685 McCoy May 7, 1946 FOREIGN PATENTS Number Country Date 538,386 Great Britain July 3, 1941 548,833 Great Britain Oct. 27, 1942 

